Filters are needed for many different applications. For example, filters can be used on engines to purify liquid, such as fuel or oil. Filters can be used on engines for purifying air to be used in combustion. Filters can also be used on generators or various industrial applications. For example, filters can be used for various gases, including propane gas. In these and other applications, it is important that the filter does not have any leaks allowing the liquid or gas to escape.
Improvements in filter designs are desirable, in particular to prevent leaking.